[R] Output of binary representation
Gabor Grothendieck
ggrothendieck at gmail.com
Sun May 17 23:21:25 CEST 2009
Also note that one can use toupper in place of as.character
in which case no other changes are required.
On Sun, May 17, 2009 at 5:07 PM, Ted Harding
<Ted.Harding at manchester.ac.uk> wrote:
> Thanks, Jim. While that is still in hex, I find I can get the binary
> represntation using Gabor's gsubfn() function, provided the A-F isw
> changed to a-f in setting up his 'binary.digits', and the output is
> explicitly cast to character:
>
> gsubfn("[0-9a-f]", binary.digits,
> as.character(writeBin(pi,raw(),endian='big')
>
> Ted.
>
> On 17-May-09 20:04:58, jim holtman wrote:
>> Are you looking for how the floating point is represented in the
>> IEEE-754
>> format? If so, you can use writeBin:
>>
>>> writeBin(pi,raw(),endian='big')
>> [1] 40 09 21 fb 54 44 2d 18
>>
>>
>> On Sun, May 17, 2009 at 1:23 PM, Ted Harding
>> <Ted.Harding at manchester.ac.uk>wrote:
>>
>>> I am interested in studying the binary representation of numerics
>>> (doubles) in R, so am looking for possibilities of output of the
>>> internal binary representations. sprintf() with format "a" or "A"
>>> is halfway there:
>>>
>>> sprintf("%A",pi)
>>> # [1] "0X1.921FB54442D18P+1"
>>>
>>> but it is in hex.
>>>
>>> The following illustrate the sort of thing I want:
>>>
>>> 1.1001 0010 0001 1111 1011 0101 0100 0100 0100 0010 1101 0001 1000
>>> times 2
>>>
>>> 11.0010 0100 0011 1111 0110 1010 1000 1000 1000 0101 1010 0011 000
>>>
>>> 0.1100 1001 0000 1111 1101 1010 1010 0010 0010 0001 0110 1000 1100 0
>>> times 4
>>>
>>> (without the spaces -- only put in above for clarity).
>>>
>>> While I could take the original output "0X1.921FB54442D18P+1" from
>>> sprintf() and parse it out into binary using gsub() or the like,
>>> of submit it to say an 'awk' script via an external file, this would
>>> be a tedious business!
>>>
>>> Is there some function already in R which outputs the bits in the
>>> binary representation directly?
>>>
>>> I see that Dabid Hinds asked a similar question on 17 Aug 2005:
>>> "Raw data type transformations"
>>>
>>> http://finzi.psych.upenn.edu/R/Rhelp02/archive/59900.html
>>>
>>> (without, apparently, getting any response -- at any rate within
>>> the following 3 months).
>>>
>>> With thanks for any suggestions,
>>> Ted.
>>>
>>> --------------------------------------------------------------------
>>> E-Mail: (Ted Harding) <Ted.Harding at manchester.ac.uk>
>>> Fax-to-email: +44 (0)870 094 0861
>>> Date: 17-May-09 Time: 18:23:49
>>> ------------------------------ XFMail ------------------------------
>>>
>>> ______________________________________________
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>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html<http://www.r-project.org/po
>>> sting-guide.html>
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>
>>
>>
>> --
>> Jim Holtman
>> Cincinnati, OH
>> +1 513 646 9390
>>
>> What is the problem that you are trying to solve?
>
> --------------------------------------------------------------------
> E-Mail: (Ted Harding) <Ted.Harding at manchester.ac.uk>
> Fax-to-email: +44 (0)870 094 0861
> Date: 17-May-09 Time: 22:06:59
> ------------------------------ XFMail ------------------------------
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
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